document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=388274>Question 388274</A>: <I><SPAN STYLE=\"word-break: break-all;\"> 3.mr. kumar lives in the eastern part of the singapore. he visits his aged parents who lives 36 km away, evry weekends. he finds that if he increases the average speed of his vehicle by 12 km/h.he could save 9 min of his travelling time. find the speed at which he travels before the increase in speed </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #274593 by </B><A HREF=/tutors/aboutme.mpl?userid=stanbon><B>stanbon(75887)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=stanbon><IMG SRC=http://www.algebra.com/images/aboutme-small.gif BORDER=0 alt=\"About Me\" VALIGN=MIDDLE></A>&nbsp;<IMG SRC=http://www.algebra.com/images/nopicture.jpg><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=274593\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> mr. kumar lives in the eastern part of the singapore. he visits his aged parents who lives 36 km away, every weekends. <BR>\n" );
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document.write( "he finds that if he increases the average speed of his vehicle by 12 km/h.he could save 9 min of his traveling time. <BR>\n" );
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document.write( "find the speed at which he travels before the increase in speed<BR>\n" );
document.write( "---<BR>\n" );
document.write( "Current Round-Trip DATA:<BR>\n" );
document.write( "distance = 72 km ; rate = x km/h ; time = 72/x hrs.<BR>\n" );
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document.write( "Changed DATA:<BR>\n" );
document.write( "distance = 72 km ; rate = (x+12) km/h ; time = 72/(x+12) hrs.<BR>\n" );
document.write( "-------------<BR>\n" );
document.write( "Equation:<BR>\n" );
document.write( "old time - new time = 9/60 hrs<BR>\n" );
document.write( "(72/x) - (72/(x+12)) = 9/60 hrs<BR>\n" );
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document.write( "Divide thru by 9:<BR>\n" );
document.write( "8/x - 8/(x+12) = 1/60<BR>\n" );
document.write( "60*8(x+12) - 60*8x = x(x+12)<BR>\n" );
document.write( "---<BR>\n" );
document.write( "60*8*12 = x(x+12)<BR>\n" );
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document.write( "x^2+12x-60*8*12 = 0<BR>\n" );
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document.write( "Positive solution:<BR>\n" );
document.write( "x = 70.13 km/h (current driving rate)<BR>\n" );
document.write( "==========================================<BR>\n" );
document.write( "Cheers,<BR>\n" );
document.write( "Stan H.<BR>\n" );
document.write( "==========\r<BR>\n" );
document.write( "\n" );
document.write( " </SPAN>\n" );
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